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Finding the Fourth Proportional to 486.35, 670.91 and 289.72

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Solution

The fourth proportional to 486.35, 670.91 and 289.72 is: 399.67

Step by Step Solution

  1. Step 1: Write the proportion equation
    486.35 : 670.91 = 289.72 : x
  2. Step 2: Convert to fraction form
    486.35/670.91 = 289.72/x
  3. Step 3: Cross multiply
    486.35x = 670.91 × 289.72
  4. Step 4: Simplify right side
    486.35x = 194,375.09
  5. Step 5: Solve for x
    x = 194,375.09/486.35
  6. Step 6: Final answer
    x = 399.67

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.